1. Field of the Invention
The present invention relates to a biometric authentication method, a biometric authentication system, an IC card, and a terminal, and more particularly to a technique of enabling providing a transition period during which old and new biometric authentication devices coexist upon updating of the biometric authentication devices, enabling reduction of burden on device providers caused by changeover of the devices and on IC card users who are required to update their biometric information, and enabling performing an authentication process even during the transition period. The present invention also relates to a technique of enabling situational control of an IC card, for example allowing deletion of biometric information for an IC card that has been invalidated for use once performing an authentication process using the card is prohibited, enabling reduction of the burden and cost of IC card administration.
2. Related Art
In recent years, along with development of a network society, identity verification in remote transactions is becoming more and more important. Password authentication is currently widely used, however, the vulnerability of password-based authentication schemes due to the fact that the number of digits of the password is small is noted. In view of this situation, attention is focused on biometric authentication as an alternative. Illustrative techniques of biometric authentication are proposed as shown below.
For example, an information processing system including an information processing device performing identity verification of a user using authentication information of the user stored in a storage device supplied to each user, and when identity verification is successful transmitting to an external device use information required for using the external device and the authentication information stored in the storage device is proposed. The storage device stores biometric characteristics information of a user. The information processing device has a reading means reading information stored in the storage device, an authentication means performing identity verification based on the biometric characteristics information read by the reading means, a transmitting means transmitting the use information and the authentication information to the external device when the identity verification by the authentication means is determined successful. See Japanese Patent Application Laid-open Publication No. 2005-38257.
Also proposed is a biometric authentication device that reads a plurality of pieces of biometric information registered in a user's IC card and performs identity verification through a combination of biometric authentications on the pieces of registered biometric information as read out. The biometric authentication device has a reading means reading an IC card in which pieces of biometric information of a user are registered beforehand, an operating means including a display unit displaying a transaction guidance screen and an input unit allowing input by an user, and a biometric authentication means reading a user's biometric information and performing biometric authentication. A transaction item of interest is selected from among the transaction items displayed on the display unit by operating the input unit, then, biometric authentication is performed on the user based on the pieces of biometric information registered in the IC card by the biometric authentication means. The biometric authentication on the user is repeatedly performed until an authentication rate as a result of the biometric authentication reaches the authentication rate set for the selected transaction item. See Japanese Patent Application Laid-open Publication No. 2007-193476.
It is required of a biometric authentication technology that, in response to changes in biometric information through variation of a living body over time, improvement in a biometric sensor technology such as an increase in the number of camera pixels and improvements in image analyzing capacity, and the like, hardware and/or software for a biometric authentication device are updated as appropriate. On the other hand, since an image format of a living body is determined depending on the hardware/software configuration of the biometric authentication device, a particular biometric authentication device and particular biometric information used for authentication by the same are used in combination. Consequently, when the hardware/software configuration of the biometric authentication device is changed, the biometric information for authentication needs to be changed accordingly.
In a system in which biometric information as a reference for authentication is stored in an IC card and biometric information read from a biometric sensor is checked against the reference stored in the IC card, along with the change or the like in the above-mentioned biometric authentication device, the biometric information registered in the IC card must be changed as well. However, it is extremely difficult to carry out changeover of biometric information stored in a user's IC card corresponding to change/update of the biometric authentication device in a practical sense.
In view of the above, there is demand for proposal of a technique that, while avoiding changeover of all the devices, burden on a provider of a biometric authentication device and on a user for updating biometric information in an IC card in correspondence with a new device can be reduced, and authentication processing is enabled even when biometric information for a new device is not yet registered during a transition period while an old device is being replaced with the new one.
Further, in the case that use of an IC card is completely invalidated due to some event such as authentication failure after a predetermined number of attempts, it is possible that the biometric information stored in the invalidated IC card cannot be deleted. In the case that this kind of IC card is discarded or stored, it is necessary to enable deletion of the biometric information in the IC card so as to reduce the risk of leakage of the biometric information.